I thought I read something about the A6 being in the upcoming apple tv that makes me think it may be less powerful than the A5 but at the speed the arm chips are progressing it really wouldn't be much of a stretch for it to be a quad core version of the A5.
I don't think why that would be the case.. for starters if they need a less powerful than A5 they can use the A4 currently used in iPT.
A6 might end up being Cortex A9MP4 (quad core), SGX 543MP4 (quad core). 512MB - 1GB RAM, depending on device (iPhone or iPad). Basically the same sort of chipset used in PlayStation Vita. Of course, I fully expect iPhone 5s, iPad 4, and probably that new Apple TV (both the integrated TV set and the set top box SKUs) to have dual core Cortex A15 and PowerVR Series 6 "Rogue". Apple will most likely label that SoC "A7".